By ZACH URNESS/Salem Statesman Journal
Coho salmon are returning in record numbers and spreading into parts of the upper Willamette Basin they’ve never historically been seen.
After a record number of the ocean-going fish entered the river above Willamette Falls last year, this year’s run could be even larger and spread the fish into more places than in the past. That’s prompted state wildlife officials to open new areas to legal coho harvest as far south as the McKenzie River this year.
Last year, a record 29,591 adult coho and 11,280 jacks, males that return a year early and tend to be smaller, returned to the Upper Willamette Basin above Willamette Falls. This year, as of Sept. 17, 11,700 adult coho have already passed Willamette Falls — ahead of last year’s pace and double the average number of fish counted for the entire season from 1991 to 2022.
Peak fishing season tends to be October to early November.
Coho salmon are not native to the Upper Willamette Basin, and it’s something of a mystery of how they arrived, fish biologists have said previously. Because they’re not a threatened or endangered species in the Upper Willamette, there are more options to harvest them, and that’s expanding this year.
Spring chinook, in contrast, are native to the Upper Willamette and have stricter rules in place.
In response to the higher numbers on coho, state wildlife officials said they’ll open “temporary regulations that open angling for coho salmon — hatchery or wild — in some areas that have not been open because coho have not historically been observed there.”
ODFW said coho harvest (hatchery or wild) will open from Oct. 1 through Dec. 31 in the following areas:
- Mainstem Willamette River from Highway 20 bridge in Albany upstream to mouth of Coast Fork Willamette
- Coast Fork Willamette and tributaries
- Middle Fork Willamette upstream to Dexter Dam
- McKenzie River upstream to Leaburg Dam
In the lower sections of the Upper Willamette, above Willamette Falls, coho harvest is already allowed, including in streams like the North Santiam, Tualatin River, Yamhill River and mainstem Willamette above the falls.
The bag limit for adult coho is two per person per day, 20 per year. The daily limit for jack coho remains five per day and jacks do not need to be tagged on the combined angling tag.
In areas that are open for retention of coho salmon in the Willamette River basin upstream of Willamette Falls, anglers with a valid 2024 Oregon two-rod validation may fish with two rods including in tributaries and flowing waters until Dec. 31.
“The expected robust return should provide good angling in areas that have traditionally supported coho-targeted angling, and the allowance for use of two fishing rods will give anglers the opportunity to improve their odds for these fish,” ODFW West Region Manager Chris Kern said in a news release.
‘Ghost fish’ of the Willamette
Once known as the “ghost fish” of the Willamette, because its runs would come and go seemingly at random, the last few years have seen growing numbers and expanded territory.
Coho have been a bright spot in an otherwise bleak outlook among Oregon’s anadromous fish. Statewide, they’re doing better than chinook and steelhead, and that’s particularly true in the Willamette Basin.
“It’s somewhat of a mystery,” Jeff Ziller, district fish biologist for the Upper Willamette Basin, told the Statesman Journal last year about why coho are thriving while other oceangoing fish struggle. “It seems to be a combination of, first off, that they’re finding better places in the ocean to feed. And second, they’re utilizing good spawning and rearing habitat in the rivers that steelhead and chinook maybe aren’t using.
“In the Willamette Valley, this is a fish that’s had its fits and starts, but in the last five years, they’re getting more and more consistent. It’s a really interesting evolutionary trend.”
Coho are native to many of Oregon’s rivers, but oddly enough, they’re not native to the upper Willamette basin, a watershed that includes numerous tributaries such as the Santiam, McKenzie and main and Middle Fork Willamette.
Historically, only winter steelhead and spring chinook salmon could migrate above Willamette Falls on high water flows and are considered native. Coho never took that journey naturally, according to officials.
There are lots of theories on how coho got established — including rogue anglers “Johnny-Appleseeding” small tributaries with coho smolts to illegally kick-start the population. The official line from the Oregon Department of Fish and Wildlife is this current run is the remnants of old stocking programs from the 1950s and 1960s.
“In the old days, we released a lot of coho in the Upper Willamette, but it never amounted to much — they never established,” Ziller said last year. “Over the decades, we’ve had some oddball years where their numbers would spike, but then they’d go back down and it wasn’t consistent.
“Now, that might have changed. They might be here to stay in a more significant way.”
Anglers taking some notice
North Santiam River fishing guide Mike Ferris has been tracking the rise of coho with enthusiasm and has brought out clients to target the fish. Because coho aren’t a protected species in the Upper Willamette, anglers are allowed to keep two per day.
Ferris said the coho could be a bright spot on the Santiam, since it has been a struggle to catch legal hatchery summer steelhead or spring chinook.
“I personally believe that this run of coho is getting better than our most recent runs of spring chinook,” he said in 2023. “I didn’t even touch a spring chinook this year and have all but given up on targeting the hatchery summer steelhead run that we used to have back in the ‘good old days.’ The people who I take fishing just want to catch a nice big fish.”
The coho that make it above Willamette Falls have traditionally stayed in the lower end of the upper Willamette basin, spawning and migrating into streams such as the mainstem Willamette, Rickreall Creek, Tualatin River, Yamhill River and the Santiam. But as their numbers exploded this year, they began migrating upstream, even making it into the McKenzie River, said Ziller.
Ziller said last year around 50 coho went over the Leaburg Dam on the McKenzie River, which had never been seen before.
“There’s no question that as you get a bigger and bigger population, there’s always a percentage that start to pioneer new regions,” Ziller said last year.
One reason coho might be finding greater success in the Upper Willamette is their ability to make use of slower, backwater habitat to spawn and rear, Ziller said.
“Their able to utilize some of those slower, backwater habitats that aren’t really used by chinook and steelhead,” Ziller said last year. “We see that in the Coast Range as well — they can take advantage of that slow-water, almost marshy or brackish habitat.”
Coho also appear to be doing better when they migrate to the ocean, although it’s not clear why, Ziller said.
Bad for chinook runs?
One difficult question for state fish biologists is whether coho might be bad for native salmon and steelhead. They are technically an invasive species. Coho can compete with native fish for nutrients or spawning ground, he said at the time.
Ziller said last year the status of coho is an “active discussion.” He noted coho and spring chinook aren’t in the river at quite the same time and don’t overlap too much. That said, as they expand, they could use habitat meant for springers.
“The bottom line is that we don’t know the effect of having their numbers growing will have,” he said. “And right now we don’t have a whole lot of control over it. It could be that they compete in separate realms and don’t impact each other’s overall numbers. We just don’t know.”
While ODFW maintains today’s coho are remnants of old stocking programs, others suggest more colorful origin stories.
Lusk said that decades ago, wildlife officials dumped coho into Detroit and Big Cliff reservoirs to see if the fish could survive going through the turbines of the dam. Apparently they did survive, he said, and helped kick-start a population in the North Santiam.
Lusk also heard somebody emptied a truckload of coho smolts into Stout Creek, a small tributary of the North Santiam between Mehama and Stayton.
“You can see them spawning in these little sidestreams and ditches,” Lusk said.
The final legend — about a Robin Hood-esque bandit stealing coho smolts from a fish hatchery and planting them in the river — is also heard in the Santiam Canyon and elsewhere.
- Zach Urness has been an outdoors reporter in Oregon for 16 years and is host of the Explore Oregon Podcast. Urness is the author of “Best Hikes with Kids: Oregon” and “Hiking Southern Oregon.” He can be reached at zurness@StatesmanJournal.com or (503) 399-6801. Find him on X at @ZachsORoutdoors.